The German midfielder feared his playing days were numbered after Wolfsburg released him in the summer following a knee injury but he was given a chance by the Toffees in November and has indicated that he is grateful to manager David Moyes for extending his short-term stay.
"When I was out in the summer I thought maybe I'd played my last game already. Now I'm back at a very, very good level in the Premier League, playing for a huge club and it's so enjoyable,” the 30-year old former Aston Villa and West Ham United man told evertontv.
"I'm over it now and I don't want to look back really. It happens and I think most players go through it. It came unexpectedly to be honest but when it did come it was something I knew I had to deal with.
"I tried to be positive and I was most of the time. Fortunately that period is over now, it's behind me and I'm just looking forward to the next few weeks and months.
"I think now I'm fully fit, there's not any problems and I think it's gone well. I spoke to the manager a few weeks ago and he told me he's pleased with my efforts."